Texture destroying arrangement for worm presses



E. BRUCKNER 3,002,227 TEXTURE DESTROYING ARRANGEMENT FOR WORM PRESSES Oct. 3, 1961 Filed Jan. 20, 1958 By @M.

Arrow/5y v United States Patent 3,002,227 TEXTURE DESTROYING ARRANGENEENT FOR WORM PRESSES Ernst Briickner, Selb, Bavaria, Germany, assignor to Gebr. Netzsch Maschinenfabrik, Selb, Bavaria, Germany, a firm Filed Jan. 20, 1958, Ser. No. 710,068 6 Claims. (Cl. 18-12) For many decades it has been endeavoured to destroy or eliminate the textures occurring when Working ceramic pastes, by modifying the construction of the presses, particularly the worms or by ancillary devices, so that they have no longer any detrimental effect in the further working of the paste. However, satisfactory results have not been obtained with any of the constructions or devices hitherto proposed.

Lately, as a result of scientific research, it has been discovered that the texture formation is caused by the fact that the relative movement, occurring during the Working of a string of paste in screw or worm presses, forms, under the influence of an external force, a layer in which the skeleton of the clay laminae collapses. Based on this knowledge, devices have recently been produced in which, by means of a number of rods arranged in the form of a grid and extending perpendicularly to the string of paste and reciprocated at a high speed, certain gels are liquefied under the effect of these movements. The viscosity of the paste is thus reduced and enables the laminated skeleton to reform, with the result that the texture is to a great extent eliminated.

These devices are, however, open to the objection that the ring with the rods, generally described as a swing grid, is built into an extension of the cylinder of the press, the cylinder extension being composed of two parts which are connected by an elastic intermediate part carrying the swing grid. This elastic intermediate part together with the swing grid is moved to and fro by an eccentric drive. The power which this requires is, however, relatively great because not only the swing grid but also the elastic intermediate part and the paste string located therein must be moved. The forces generated thereby are so great that specially insulated foundations are necessary to take up the vibrations.

According to the invention these objections are overcome by the fact that, following the press cylinder an oscillating stirrer such as a wire cage is arranged in the extension thereof, which can be of any desired shape and adapted to the paste to be worked, or a flat grid which is carried by a shaft guided by the worm shaft constructed as a hollow shaft, and to which cage or grid a reciprocating motion is imparted by an eccentric drive. The eccentric drive is at the same time connected by a connecting rod to a lever mounted on the shaft so that it engages the lever at adjustable points and the amount of swing can be varied. An oscillating device or unit can also act on the shaft instead of the eccentric drive. The drive may also be so constructed that the shaft carrying the cage or swing grid rotates with the worm shaft and in so doing carries out a supplementary reciprocating movement.

A device according to the invention is illustrated by way of example in the accompanying drawing, in which FIG. 1 is a longitudinal section showing the hollow shaft with the texture destroying unit and the driving shaft passing therethrough;

3,002,227 Patented Oct. 3, 1961 "ice FIG. 2 shows the eccentric drive in side elevation, and

FIGS. 3 and 4 show end and longitudinal sectional views, respectively, of a texture destroying arrangement of grid-like construction.

A shaft b serving as carrier for the press worm a is constructed as a hollow shaft. Bearings c are mounted on both ends of this hollow shaft for receiving a throughshaft d which on the one hand can be rotated at high speed with constantly changing direction of rotation by means of a lever system e, a connecting rod 1 and an eccentric g, and on the other hand carries an inside oscillator h rigidly connected with it and disposed beyond the end of the worm in the path of the paste string passing through the press. The amplitude of the movements can be chosen of such size by shifting the point where the connecting rod f engages the lever system e. This inside oscillator h can be adapted in shape according to the characteristics of the paste to be Worked. It can, as shown in FIG. 1, consist of a cage formed by Wires which are arranged in spiral shape so that, in rotating, they overlap and sweep over the paste string on its entire diameter. It may, however, be formed by a ring i in which through-rods k are fixed, as shown in FIGS. 3 and 4.

1 claim:

1. A texture destroying arrangement for worm presses for ceramic pastes, comprising in combination with a press cylinder, a worm arranged in said cylinder, an inside oscillating stirrer in the interior of said cylinder following said press worm, and means for imparting rotary oscillating movement to said stirrer constantly changing its direction.

2. An arrangement for worm presses as set forth in claim 1, wherein the worm is carried by a hollow shaft, a second shaft extends through said hollow shaft and the oscillating stirrer is rigidly connected to this second shaft and driven thereby.

3. An arrangement for worm presses as set forth in claim 1, wherein the worm is carried by a hollow shaft, a second shaft extends through said hollow shaft, the oscillating stirrer is rigidly connected to this second shaft and driven thereby, and the drive of said second shaft comprises an eccentric and a lever system with a variable point of engagement actuated by said eccentric.

4. An arrangement for worm presses as set forth in claim 1, wherein the worm is carried by a hollow shaft, a second shaft extends through said hollow shaft, the oscillating stirrer is rigidly connected to this second shaft and driven thereby, and the drive consists of an oscillating device.

5. An arrangement for worm presses as defined in claim 1, wherein said stirrer comprises a cage formed of a plurality of spirally-shaped wires.

6. An arrangement for worm presses as defined in claim 1, wherein said stirrer comprises a ring-shaped member and a plurality of rods extending across said member.

References Cited in the file of this patent UNITED STATES PATENTS 742,971 Cummer Nov. 3, 1903 1,677,808 Alassio et al. July 17, 1928 1,775,735 Reker Sept. 16, 1930 2,144,213 Bassett et a1. Ian. 17, 1939 2,469,999 Stober May 10, 1949 2,488,129 La Lande Nov. 15, 1949 

